It followed several bids from Kent schools for a share of a first £50m fund, where only Rochester Grammar School was successful in applying for some of the cash.

Cllr Martin Potter (Con) said: “We have provided 650 additional places at our existing grammar schools – which are now reaching their ideal capacity – which means one of two things.

“We need either a grammar or satellite school – or we reduce that 25% provision. This administration is not willing to reduce it because the benefits are clear.

“Students from the most deprived backgrounds might do better in a grammar school setting compared to another, and we need to ensure provision remains in place for those students regardless of income and background.”

The council decided at a meeting on Thursday night it will also write to Medway’s three MPs in the hope of gaining their support for the proposal.

Labour abstained from voting on the motion after its own proposal to have a “full review of secondary education provision” was rejected by the ruling party.

The government is inviting bids for a £50m fund to expand grammar schools. Stock image

Cllr Clive Johnson (Lab) told colleagues: “If we’re short of school places, we need to look at the system as a whole – the academically able, those whose talents lie in other areas, and those with special needs.”

The Tories were also accused of “picking and choosing” its support of the Towns’ schools, while opposition councillors also bemoaned the loss of £26 million central government funding for education in Medway.

Cllr Vince Maple (Lab) added: “We on this side want to make sure all of our schools succeed and that’s what this amendment does.

“It gets us to a position as a council to make sure our secondary provision is the very best it can be – and that’s despite the cuts year-on-year over the last nine years.”

The proposal was rejected however, with Cllr Andrew Mackness (Con) described Labour’s position of “not supporting grammar schools” as “shameful”, insisting an annual sufficiency report already ensured non-selective provision was available.

He added: “There is no current mechanism that is clearly understood to ensure there will be sufficient grammar school places in Medway in the future. We want to ensure we do that, we want to ensure there is a mechanism put in place.”